I thought this was some kind of proverb—or the beginning of one—or something... so I Googled it, and it's found in many things. It's in the Bible. It's the title of several songs. It's the name of a non-profit organization (probably more than one). It's the name of a board game. It's probably been used in stories, poetry, verses, etc.
I just like the way it's stated. It has been stated many ways, such as, "Don't be afraid," "Don't be scared," "Fear not," "Be brave," and so on. But here, there's such an emphasis on the word, "not," to me (which is why I made it visually so). I don't know why I like it, but I just like what I like, and sometimes that's all that need be said. :)